VLA observations of synchrotron radiation at 15 GHz

We present observations of the synchrotron radiation from Jupiter obtained in July 2004 with the Very Large Array at a frequency of 15 GHz. The array was in its most compact (D) configuration and the distance to Jupiter was 6.077 AU, making the apparent size of Jupiter relatively small, and favorable for such observations. We measured a total synchrotron radiation flux density of 1.26 ± 0.12 Jy , scaled to a distance of 4.04 AU, which was 2.4% of the total flux density from the planet. Our results agree, within the uncertainties, with a previous VLA measurement ( 1.5 ± 0.15 Jy in March 1991 [de Pater, I., Dunn, D., 2003. Icarus 163, 449–455]); both values are a factor of 3–3.5 higher than the flux density reported from Cassini data in 2001 [Bolton, S.J., and 20 colleagues, 2002. Nature 415, 987–991].